Optical switch

ABSTRACT

An optical switch includes a plurality of transmitting devices with a plurality of optical fibers. A plurality of receiving devices are provided that include a plurality of optical fibers. At least a portion of the transmitting devices simultaneously focus and direct transmitter output beams from the plurality of transmitting devices to the plurality of receiving devices.

CROSS-REFERENCE TO RELATED APPLICATIONS

[0001] This application claims benefit of 60/214,837 filed Jun. 28,2000, which application is fully incorporated herein as if set forth inits entirety.

BACKGROUND OF THE INVENTION

[0002] 1. Field of the Invention

[0003] This invention relates generally to optical communications, andmore particularly to all-optical switching of fiber networks.

[0004] 2. Description of the Related Art

[0005] A critical technology in enhancing speed and bandwidth incommunication systems is All-Optical switching, a primary goal of thetelecommunication industry. Optical cross-connects are the enablingdevices for the planned all-optical communication networks. They connecthigh-capacity fiber optic communication links coming into a particularhub with any of hundreds of outgoing channels. In doing so they solvetwo major problems. First, they provide controlled connections amongnumerous intermediate links to create a continuous optical pathwaybetween endpoints anywhere in the network, optimizing the stream of dataand reducing the cost of service. Secondly, they protect the network inthe event of catastrophic failure of an intermediate link byinstantaneously re-routing a circuit. An all-optical network will beeasier to manage and more reliable while reducing the cost of bandwidth.

[0006] There are several types of All-Optical switches known in the art.The classification of optical switches is presented in FIG. 1. Amongthem there are switches based on light birefringence phenomenon,switches utilizing light polarization in liquid crystals, switchesutilizing bubbles in capillaries, electromechanical switches, andmirror-based switches.

[0007] Many 1×N switch architectures are based on a combination oftwo-state gates in a tree like structures. For N input channels Nsimilar structures are required. It is clear that N×N switch requires N²gates. Moreover, in such a switch each of N output channels requiresadditional couplers and therefore increases both cost and optical lossesin this switch architecture.

[0008] The operation of birefringent switches, typically based onlithium niobate or titanium niobate crystals, is polarization sensitive,and thus these switches require polarization-preserving optical fibers,and also require careful input/ output waveguide mode matching in theoptical system. Lithium niobate based switches have relatively largeinsertion loss and provide only a moderate degree of channel isolation.Besides, such switches require complicated fabricating processes.Examples of such switches can be found in the U.S. Pat. No. 4,976,505and U.S. Pat. No. 5,946,116.

[0009] Liquid Crystal Optical Switches offer relatively high on/offratios and relatively low optical insertion losses. But they requirepolarized light. Additionally, liquid crystal switches have certainenvironmental limitations including limited operating temperature rangeand environmental degradation. It is generally agreed upon that thetechnology lends itself only for small-size switching arrays. Examplesof such switches can be found in publication Bawa et al., “Miniaturizedtotal-reflection ferroelectric liquid-crystal electro-optic switch,”Appl. Phys. Lett., vol. 57, No. 15, pp. 1479-1481, Oct. 8, 1990 and inthe U.S. Pat. No. 5,132,822.

[0010] Another architecture, based on waveguides and gas bubbles influid media, is described in the U.S. Pat. No. 6,055,344. At eachswitching point, an input waveguide intersects an output waveguide at afluid-filled trench. If the intersection is filled by liquid then thelight passes straight through the intersection. When a gas bubble isplaced in the intersection then light reflects to the output waveguide.It is obvious that an N×N channel switch also requires N² gates. Gasbubble based switches have certain environmental limitations includingoperating temperature range and environmental degradation. Insertionloss for such switches greatly depends on optical path and can vary manytimes within one switch. A similar architecture, based on waveguides andmirrors, is described in the U.S. Pat. No. 5,960,132.

[0011] Optical switch utilizing thermo-optical attenuators as the gatesis described in “Silica-based optical- matrix switch with intersectingMach-Zehnder waveguides for larger fabrication tolerances” by M. Kawachiet al, Conference OFC/IOOC '93, Feb. 21-26, 1993, San Jose, Calif.(U.S.A.), paper TuH4. Each input guide splits on two guides. Aftersplitting each guide will have a gate, which can either open or closethe guide. It can be shown that the total number of required gates foran N×N switch is 2 N².

[0012] Another technology is based on a sliding mirror between two orthree fibers, which can potentially be used as a variable opticalattenuator or as an optical switch in small-size switching arrays. SeeU.S. Pat. No. 6,031,946.

[0013] Another group of optical switches utilizes multi-state switchingelements. One of the great advantages of open space architecture is thatthe light beams can physically cross each other without interference ofthe signals transmitted by both beams. The light beams carryinginformation are transparent to each other. This is a unique property oflight, which allows building switches with absolutely differentarchitecture not possible in the electrical wire world.

[0014] The majority of current open space optical switching technologiesare based on MEMS micro-mirrors. Schematically this principle is shownin FIG. 2 . The light beams 10 from the input fibers 12 are focused withcollimators 14 on the first set of mirrors 16, where they areredirected, as shown in 18, onto a second set of mirrors 20, which intheir turn are redirecting the beams 22 into required output collimators24 and then to the fibers 26. N×N optical switch based on thisarchitecture requires 2N mirrors. Optical attenuation is in the range of5 to 10 dB and they require at least two major optical alignments:between the transmitting array and the first mirror array and betweenthe second mirror array and the receiving array. This architecture iscomplicated mechanically, optically and electronically.

[0015] Some of these MEMS micro-mirror arrays are based on surfacemicromachining technology. These devices have few disadvantages. Thereported switching time is relatively slow. The optical losses are high.A large portion of these losses is inherent to this technology. Forexample, a non-flatness of the mirror is one of the sources of opticallosses.

[0016] Other technologies use micro-mirrors based on bulk siliconmicromachining. Bulk micro-machined mirrors with Gimbals suspension areinherently extremely fragile due to the relatively large mass of themirrors, which are suspended by very thin beams. This results in lowyield, high cost, and low reliability. See U.S. Pat. No. 5,629,790incorporated fully herein by reference.

[0017] In another approach the switching or channel selection isachieved by means of a prism. Optical losses are moderate but thearchitecture and structure of the switch is complicated. See U.S. Pat.No. 5,999,669 and U.S. Pat. No. 6,005,993.

[0018] Another approach of redirecting the light beams between thetransmitting and receiving arrays is based on lateral movement of themicro-lenses in front of collimators. However, it requires large spacearound the lens and the efficiency of the real estate utilization in thearray is very low. See, for example: H. Toshiyoshi, Guo-Dung J. Su, J.LaCosse, M. C. Wu, “Microlens 2D Scanners for Fiber Optic Switches”,Proc.3rd Int'l Conf. On Micro Opto Electro Mechanical Systems (MOEMS99),Aug. 30-Sep. 1, 1999, Mainz, Germany, pp. 165-167.

[0019] In electromechanical optical switches the input optical fibersare moving relative to the output optical fibers. Electromechanicalswitches do not require mirrors and therefore, do not requirecorresponding optical alignments and have smaller optical losses.However, macro actuators, for example step motors, are usually used inelectromechanical switches as actuators. As an alignment of the fibersis critical in such systems, providing this precise and reproduciblealignment with the motors is a big challenge. Another limitation of theelectromechanical switches is that it is difficult to movesimultaneously and independently more than one input fiber with respectto N output fibers. Besides, actuators used in these optical switchestypically have only one degree of freedom, i.e. they allow circularmotion of the fiber. Although these switches historically appearedfirst, they are usually 1×N switches, mechanically complicated,unreliable and slow. Examples of electromechanical optical switches aredescribed in U.S. Pat. No. 4,378,144, U.S. Pat. No. 5,920,665.

[0020] Another optical switch is described in U.S. Pat. No. 4,512,036.In this switch, the end of the fiber is bent in two dimensions relativeto a lens, which focuses the beam to a receiving lens. Piezoelectricactuators perform the bending of the fiber. Besides being costly, thedimensions of these beam steering units affect the overall size of theoptical switch. As piezoelectric actuators have certain limitations inthe displacement, this type of switch can be used only for relativelylow port-count. The main disadvantage of this switch is that it istrying to combine different incompatible technologies in one device.They can not be integrated in one batch fabricating process. As aresult, the technology of assembling is very complex, performance andreliability are low and expected cost is large.

[0021] An enabling development for all-optical systems is the concept ofOptical MEMS. An acronym for Micro-Electro-Mechanical Systems, MEMS is aterm used to describe a concept—Microsystems that monolithicallyintegrate microstructures, sensors, actuators or optical components,like mirrors, lenses, couplers, etc., with associated mechanical,optical and electronic functions. MEMS are now used throughout the worldin an ever-expanding range of applications in automotive, industrial andconsumer products. Communication technology and specifically opticalcommunication will be revolutionized with Optical MEMS. One of OpticalMEMS switches is disclosed in this patent application.

[0022] There is a need for an optical switch with a larger number ofswitching channels that have the same optical loss. There is a furtherneed for an optical switch with smaller optical loss in each switchingchannel.

SUMMARY

[0023] Accordingly, an object of the present invention is to provide anoptical switch with a larger number of switching channels with the sameoptical loss.

[0024] Another object of the present invention is to provide an opticalswitch with smaller optical loss in each switching channel.

[0025] Yet another object of the present invention is to provide anoptical switch with faster switching.

[0026] Still another object of the present invention is to provide anoptical switch with lower cost of switching per channel.

[0027] Yet another object of the present invention is to provide anoptical switch that has higher reliability.

[0028] A further object of the present invention is to provide anoptical switch with lower sensitivity to vibrations.

[0029] Another object of the present invention is to provide an opticalswitch with lower temperature sensitivity of optical switching.

[0030] A further object of the present invention is to provide a smallersize optical switch.

[0031] Yet another object of the present invention is to provide anoptical switch with a simpler architecture. Another object of thepresent invention is to provide an optical switch with an improvedmovable microstructure.

[0032] Yet a further object of the present invention is to provide anoptical switch with a more effective actuator of movable microstructure.

[0033] Another object of the present invention is to provide an opticalswitch that has higher sensitivity sensors for a closed loop controlsystem.

[0034] Yet another object of the present invention is to provide amulti-position open loop control system for an optical switch.

[0035] A further object of the present invention is to provide a higherlevel of integration of different components for an optical switch.

[0036] Still another object of the present invention is to provide ahigher level of integration of different MEMS, electronic andmicro-optical components of an optical switch.

[0037] Yet another object of the present invention is to provide opticalswitch with fewer components.

[0038] Another object of the present invention is to provide an opticalswitch that has less optical alignments of components.

[0039] These and other objects of the present invention are achieved inan optical switch that includes a plurality of transmitting devices witha plurality of optical fibers. A plurality of receiving devices areprovided that include a plurality of optical fibers. At least a portionof the transmitting devices simultaneously focus and direct transmitteroutput beams from the plurality of transmitting devices to the pluralityof receiving devices.

[0040] In another embodiment of the present invention, a method foroptical switching between input fiber channels output fiber channelsprovides a plurality of transmitting devices and a plurality ofreceiving devices. At least a portion of the transmitter output beamsare simultaneously focused and directed from the plurality oftransmitting devices to the plurality of receiving devices.

DESCRIPTION OF THE FIGURES

[0041]FIG. 1 is a schematic diagram of prior art optical switches.

[0042]FIG. 2 is a prior art schematic diagram that illustrates openspace optical switching technologies based on MEMS micro-mirrors.

[0043]FIG. 3 is a schematic diagram of one embodiment of an opticalswitch of the present invention.

[0044]FIG. 4 is a schematic diagram illustrating the architecture of oneembodiment of an optical switch of the present invention.

[0045]FIG. 5 illustrates an enlarged portion of the FIG. 4 opticalswitch.

[0046] FIGS. 6(a) and (b) are schematic diagrams illustratingembodiments of transmitting directing devices of the present invention.

[0047] FIGS. 6 (c)-(e) are schematic diagrams illustrating differentkinds of optical bodies useful with the present invention.

[0048] FIGS. 7(a)-(f) are schematic diagrams illustrating differentgeometric shapes of optical bodies useful with the present invention.

[0049] FIGS. 8(a)-(c) are schematic diagrams illustrating an embodimentof fiber connectors of the present invention.

[0050] FIGS. 9(a)-(h) are schematic diagrams illustrating various lenssystem embodiments of the present invention.

[0051] FIGS. 10(a)-(f) are schematic diagrams illustrating additionallens system embodiments of the present invention.

[0052] FIGS. 11 (a)-(d) are schematic diagrams illustrating variousembodiments of focusing devices of the present invention.

[0053]FIG. 12 is a schematic diagram illustrating one embodiment of atransmitting directing device of the present invention.

[0054]FIG. 13 is a schematic diagram of a gimbals suspension of themoveable part of a transmitting device useful in one embodiment of thepresent invention.

[0055]FIG. 14 illustrates the overload protection, of one embodiment ofthe present invention, against acceleration applied in either X or Zdirection.

[0056]FIG. 15(a) is a top view illustrating one embodiment of a fibercell of a transmitting directing device with an electrostatic actuatoraccording to one embodiment of the present invention.

[0057]FIG. 15(b) is a cross-section of the FIG. 15(a) one-fiber cell.

[0058]FIG. 16(a) is a top view and a cross section of the one-fiber cellof the transmitting directing device with an electrostatic actuatoraccording to another embodiment of the present invention.

[0059]FIG. 16(b) is a cross section of the FIG. 16(a) one fiber cell.

[0060]FIG. 17(a) is a top view and a cross section of the one-fiber cellof the transmitting directing device with an electrostatic actuator anda suspension using diagonal beams.

[0061]FIG. 17(b) is a cross section of the FIG. 17(a) one fiber cell.

[0062]FIG. 18(a) is a top view illustrating one embodiment of anactuator used with the present invention.

[0063]FIG. 18(b) is a cross sectional view illustrating one embodimentof an actuator with a planar suspension used with present invention FIG.18(c) is a cross sectional view illustrating one embodiment of anactuator with non-uniform beam suspension and actuation movable plateslocated in different plane relative to suspension used with the presentinvention.

[0064]FIG. 18(d) is a cross sectional view illustrating one embodimentof an actuator with spring like suspension and actuation movable plateslocated in different plane relative to suspension used with the presentinvention.

[0065]FIG. 18(e is a cross sectional view illustrating one embodiment ofan actuator with non-uniform beam suspension and actuation movableplates having additional cylindrical surface providing increasedactuation force used with the present invention.

[0066]FIG. 19 is a three-dimensional view of the suspension illustratedin FIG. 18(e).

[0067]FIG. 20 is a three-dimensional view of the suspension shownillustrated in FIG. 18(d).

[0068]FIG. 21(a) illustrates an example of electrostatic actuation ofthe optical switch with eight electrodes for eight angular positions ofthe movable part of the actuator.

[0069]FIG. 21(b) is a cross section view of FIG. 21(a) electrostaticactuation of the optical switch.

[0070]FIG. 22(a) is a top view of an actuator useful in making amushroom like suspension for use with the present invention.

[0071]FIG. 22(b) is a cross sectional view of an actuator with a flatmushroom hat for use with the present invention.

[0072]FIG. 22(c) is a cross sectional view of an actuator with a fiberthat extends over the FIG. 22(b) mushroom hat.

[0073]FIG. 22(d) is a cross sectional view of an actuator with lenssystem on the top of the FIG. 22(b) mushroom hat.

[0074]FIG. 22(e) is a cross sectional view of an actuator with anadditional cylindrical surface on the top of the FIG. 22(b) mushroom hat

[0075]FIG. 22(f) is a cross sectional view of an actuator with anadditional cylinder and lens on the top of the FIG. 22(b) mushroom hat.

[0076] FIGS. 23(a)-(f illustrate different embodiments of the lightredirecting devices of the present invention.

[0077] FIGS. 24(a)-(f) illustrate different embodiments of the moveableparts of the fiber useful with the present invention.

[0078] FIGS. 25(a)-(b) illustrate different embodiments of opticallytransparent media that can be employed with the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0079]FIG. 3 illustrates one embodiment of an optical switch 30 of thepresent invention. The FIG. 3 embodiment includes five major components,a transmitting unit, hereafter a “transmitting array” 32, an opticaltransparent media 34, a receiving unit, hereafter a “receiving array”36, a control system 38 and a packaging 40. Transmitting and receivingarrays 32 and 36 each include an optical body 42, a fiber connector 44,a cavity 46, a lens 48, a focusing device 50 and a transmittingdirecting device 54.

[0080]FIGS. 4 and 5 illustrate one embodiment of architecture of opticalswitch 30. Included is transmitting array 32 with transmitting directingdevices 54 and incoming fibers 12. Light beams from transmittingdirecting devices 54 travel through optical transparent media 34 toreceiving devices 56, which are mounted in receiving array 36. Receivingdevices 56 focus the light into output fibers 26. Transmitting andreceiving arrays 32 and 36 are controlled with control circuit 38. Inone embodiment, each element of optical switch 30 is included in package40.

[0081] In one embodiment of the present invention, the entire opticalswitch 30 can be micro-packaged to include transmitting array 32,optical transparent media 34, receiving array 36, control system 38 aswell as the fiber connectors at the input and out. The present inventionutilizes MEMS based technology and packaging to achieve full integrationof all or a portion of the optical, electronic and mechanical componentsof optical switch into one system fabricated that is fabricated in oneintegrated process.

[0082] Transmitting directing device 54 is shown in more detail in FIGS.6(a) and 6(b). Array 32 or the body of array 32 includes cavities 46 and47. Incoming fiber 12, with protective layer 58, is fixed intransmitting array 32 with fixture 59. Fixture can include a variety ofdifferent devices and materials, including but not limited to anadhesive material. The flexible end of fiber 60 is connected to opticalbody 42 with optical connector 62. Optical connector 62 can be a splice,an optically transparent adhesive and the like. Fiber 60 is connected tooptical body 42 at a location 64, which is positioned in optical body 42in front of a location 66 of lens 68. The portion of optical body 42connected with connector 62 couples optical body 42 with suspension 72and 73. Suspension 72 and 73 are connected to actuators 74 and 75 whichare controlled by actuator drivers 76 and 77. Drivers 76 and 77 supplypower to actuators 74 and 75, which in turn apply forces, for example anelectrostatic force to suspension 72 and 73. Actuator 75 applies apulling force to suspension 73, connector 62 then moves lens 68 andoptical body 42, along with fiber 60. This results in a redirection ofthe light beam.

[0083] FIGS. 6(c), (d) and (e) illustrate different embodiments ofoptical body 42. As illustrated in FIG. 6(c), optical body 42 can bemade from solid optically transparent material 78. In this embodiment,optical body 42 is located in cavity 46, 47. This provides movement ofoptical body 42 in a two-dimensional, eyeball like configuration.

[0084]FIG. 6(d) shows that optical body 42 can be made from plastic film80 filled with transparent liquid 82. Alternative, as illustrated FIG.6(e), optical body 42 can be made from framework 84 with an interiorthat includes an optically transparent air or clean gas 86. Light fromthe end of fiber 88 is then collected and focused by lens 68.

[0085]FIG. 7(a)-(f) also illustrates different shapes and types ofoptical bodies 42. In FIG. 7(a), a portion of optical body 42 has aspherical shape. Optical body 42 can have a funnel type of geometricconfiguration where fiber 60 and optical body 42 move. Cavity 46 can befilled with liquid material 90. In this embodiment, optical body 42,with its spherical shape, behaves similar to an eyeball and has anadvantage of not requiring spring suspension. Spring suspension usuallyserves two functions, mechanical shock protection and providing angulartilt of optical body 42. In the FIG. 7(a) embodiment, the tilt ofoptical body 42 does not require large displacement or shock protection.Liquid material 90 in cavity 46 provides lubrication between opticalbody 42 and cavity 46 in the process of rotating optical body 42 forredirecting the light beam.

[0086]FIG. 7(b) illustrates and embodiment where optical body 42 has aconical geometric configuration. If the shape of the cone corresponds tothe shape of the diverged light beam exiting from the end of fiber 60 tolens 68, then the mass of optical body 42 can be minimized for aselected optical body 42 material. In this embodiment, cavities 46 intransmitting array 32 have cylindrical geometric configurations. Ifoptical body 42 is suspended by springs there is no need for a funnellike optical cavity 46, where the spherical body seats, and opticalcavity 46 can be cylindrical. In FIG. 7(c) optical body 42 isillustrated as having funnel geometry, which can be easier to fabricatein a batch process.

[0087] As illustrated in FIG. 7(d), optical body 90 is cylindrical whereit is coupled at the bottom with fiber 60. Lens 68 is positioned at theopposing side of the body. The space between fiber 60 and lens 68 can befilled with an optically transparent material 92 which can decrease theheight and mass of optical body 90.

[0088] The embodiment of FIG. 7(e) is similar to that of FIG. 7(d)except that the inside of the cylinder is not completely filled withoptically transparent material. In this embodiment, opticallytransparent material 94 is used as a mechanical and optical connector 94between fiber 60 and lens 68, and decreases the mass of the cylindricalbody.

[0089] In the FIG. 7(f) embodiment, optical body 90 includes a system oflens 68 and 69. Fiber 60 can be connected with lens 68 with a very thinlayer of optically transparent material 96. The space between lenses 68and 69 can also be filled with optically transparent material 92. Theuse of lenses 68 and 69 and the additional optical transparent material96 decreases the size and the mass of the movable parts of opticalswitch 30.

[0090] The embodiments of FIGS. 8(a)-8(c) illustrate the relationship ofconnector 62, fiber 60 and optical body 42.

[0091] In FIG. 8(a) fiber 60 extends into and is connected in cavity 98with optically transparent and mechanically strong adhesive 94.Connector between optical body 42 and fiber 60, can be made as a solidsingle body, as illustrated in FIG. 8(b). In this case, lens 68 andfiber 98 are made as a single optical body 42. Fiber 98 is connected tofiber 60.

[0092] In FIG. 8(c), optical body 42 can be made from plastic film 80and filled with liquid 82. In this embodiment, connector of body andfiber can be made as a continuation of optical body 42 as a hose 81.Fiber 60 is inserted in hose 81 making an optical and mechanicalconnection with body 42.

[0093] The light beam coming from the transmitting fiber should becollimated or focused for being redirected through the open spacebetween transmitting and receiving arrays 32 and 36. A variety ofdifferent lenses can be used for this purpose including but not limitedto, GRIN lenses, regular micro-lenses, diffraction grated lenses,micro-Fresnel lenses and the like. Disadvantage of GRIN and micro-lensesis that they have larger masses. Fresnel and grating micro-lenses arepreferable because they are lighter.

[0094] The size and the material of the lens is determined by a varietyof factors including but not limited to, the required diameter of thebeam size, mass of the focusing system, required optical properties andthe like. In one embodiment, the size of the lenses used with opticalswitch 30 is in the millimeter and sub-millimeter range. Differentmaterials can be used for the lenses depending on, the requiredwavelength, refractive index and technological processes. Suitablematerials include but are not limited to different kinds of glass,semiconductor materials, different polymers and the like.

[0095] FIGS. 9(a)-9(h) illustrate different embodiment of lenses thatare employed at the output end of optical body 42 of transmitting array32, and at the input end of optical body 42 of receiving array 36.

[0096] In FIG. 9(a), a simple one lens 68 is coupled to connector 94 andmoveable part 70, and is optically and mechanically connected at the endof fiber 60 with optically transparent material 94. A change in theangular position of movable part 70 moves lens 68 and the distal end offiber 60, resulting in a redirection of light beam 100. Lens 68 can bemade from different materials including but not limited to, glass,polymers, silicon and the like. Making lens 68 from the same structuralmaterial as the other components, for example silicon, has an advantageof direct integration of lens 68, or system of lenses, with other MEMScomponents, as illustrated in FIG. 9(b).

[0097] Referring now to FIG. 9(c), a system of lenses 68 and 69 arepositioned in moveable part 70 at a selected distance in order toimprove the collimating or focusing of the light beam. Lens 68 can becoupled to the distal end of fiber 60 with an optically transparentadhesive 94. In FIG. 9(d), lens 102 is asymmetric and deflects the lightbeam to a certain angle in a neutral position of movable part 70. Inthis embodiment, lens 68, which serves as a focusing lens, can becoupled to the distal end of fiber 60 with an optically transparentadhesive 94.

[0098] As illustrated in FIG. 9(e) when the size of lens 104 iscomparable with the diameter of fiber 60, lens 104 can be positioned atthe distal end of fiber 60 and directly connected to moveable part 70.In other embodiments, shown in FIG. 9(f), lenses 104 or 105 can be madefrom fiber 60 itself.

[0099] The system of lens illustrated in FIG. 9(g) is similar to 9(c),and the space between lenses 68 and 69 can be filled in with anoptically transparent material 92 that has required optical propertiesin order to optimize the focusing or collimating of the total lightbeam. For example, optically transparent material 92 can change thediameter and the length of the focuser. This affects the performancecharacteristics of the lens system. FIG. 9(h) illustrates a lens 68 madefrom elastic optically transparent polymer films 106 and 108. The insidevolume of lens 68, in this embodiment, is filled with a transparentliquid 110 which can be delivered to the inside of lens 68 through acapillary channel 112. Lens 68 is mounted on moveable part 70 where theend of fiber 60 is also mounted and at a certain distance from lens 68.The space between the distal end of fiber 60 and lens 68 can also befilled with an optically transparent liquid in order to optimize themechanical and optical properties of the lens system.

[0100] FIGS. 10(a)-10(f) illustrate different embodiments ofmicro-collimators or micro-focusers that are based on eithermicro-Fresnel lenses or grating micro-lenses.

[0101] In the FIG. 10(a) embodiment, a simple collimator/focuser isbased on one lens 120 that is in a fixed relationship to moveable part70. The distal end of fiber 60 is also fixed to movable part 70. Lens120 can have a grating surface 122 that is formed on the outside of thecollimator/focuser. The space between the distal end of fiber 60 andlens 120 can be filled with an optically transparent material 92 thathas optical properties for optimizing the collimator geometry. In someinstances, for example when the grating lens is fabricated on one waferthat is bonded to another wafer with other MEMS components, it ispreferable to position gratings 122 on the inside surface of lens 120,as shown in FIG. 10(b).

[0102] Both surfaces 122 and 124, of lens 120 can be grating surfaces inorder to provide an improvement in the optical properties of thefocuser/collimator. This is illustrated in FIG. 10(c).

[0103] With the embodiment of FIG. 10(d), two grating lenses 120 and 126are fixed in moveable part 70. Fiber 60 is also optically andmechanically connected with movable part 70. The space between lenses120 and 126 can be filled with an optically transparent material 128.The use of a two-lens system provides greater flexibility in designingrequired optical properties of the focuser/collimator.

[0104] Referring now to FIG. 10(e), a system of three lenses, 120, 126and 130, are used for greater focusing and collimating ability. It willbe appreciated that the grating properties of lenses 120, 126 and 130can be different as well as the distance between the lenses. The FIG.10(e) embodiment provides greater flexibility in achieving the requiredoptical properties of the focuser/collimator. An additional telescopiclens 134 can be used for decreasing the length and the mass of thefocuser/collimator. When the same structural material is used for lens120 and the other components, then the structure of the integratedmicro-collimator can look like that illustrated in FIG. 10(f) .

[0105] When the size of transmitting and receiving arrays 32 and 36 islarge (see FIG. 4) or comparable to the distance between transmittingand receiving arrays 32 and 36, then the deflection angle or tilt oftransmitting and receiving arrays 32 and 36 should be large. In thiscase if the light beam is focused not optimally, then the size of thespot of the beam on receiving array 36 can change significantly betweenthe center of receiving array 36 and its periphery. In this case it canbe desirable to provide an adjustable focusing of the lenses so that thediameter of the light spot on receiving elements of array 36 would havethe same size. This also requires refocusing of the light beam and canbe achieved with adjustable focus lenses, as illustrated in FIGS. 11(a)-11(c).

[0106]FIG. 11(a) illustrates the principle of a lens with an adjustablefocus. This lens consists of two optically transparent polymer films 106and 108 that are fixed on moveable part 70. An interior volume betweenpolymer films 106 and 108 can be filled with an optically transparentliquid 110. The same optically transparent liquid 110 is in a capillarychannel 112 that is coupled to chamber 138 where actuator 139 ispositioned. Chamber 136 is filled with optically transparent liquid 110and coupled, through channel 140, to another chamber 141. Chamber 141includes a pressure sensor 142. One of the polymer films 106 and 108 ismechanically and optically connected to the end of fiber 60 withoptically transparent material 94. Actuator 139, which can be a thermalactuator, changes the pressure of the optically transparent liquid 110in chamber 138. This pressure is equalized and changes the pressure inchamber 136. Due to the changing of pressure films 106 and 108 changetheir shape resulting in a change in the radius and focus of the lensdefined by films 106 and 108. The value of the pressure inside the lenscan be sensed by a pressure sensor 142. The pressure is proportional tothe curvature and focal distance of the lens.

[0107]FIG. 11(b) illustrates a combination of the FIG. 11(a) focusinglens with the grating lenses with grating films 143 are positioned onthe outside of the lens and the inside of optical body 94. When pressureinside the lens changes, and the curvature of the polymer grating lenschanges, then a change of the focal distance of the lens can occur dueto two factors, change of the curvature of the regular lens and changeof the grating geometry in the grating lens. The combined effect offocal distance variation can be larger.

[0108] Variations in pressure applied to grating films 143 can be usedfor correction of the light beam characteristics. A grating 144 can belocated on the interior surface of a film 145 that is inside the lens,as shown in FIG. 11(c), or from both sides of film 145, illustrated inFIG. 11(d).

[0109] Referring now to FIG. 12(a), one embodiment of the cross-sectionof an one-fiber cell 162 of transmitting directing device 54 isillustrated. One-fiber cell 162 contains base member 32 coupled to amicro-machined die 153. Micro-machined die 153 includes a frame 154 andmovable parts 156 and 158. Micro-machined die 153 can be made fromsilicon using some known MEMS micromachining processes. Lens 68 isconnected with movable parts 156 and 158. Lens 68 is preferably amicro-lens located in the central area of movable parts 156 and 158.Fiber 12 is connected with base member 32 and movable parts 156 and 158.Fiber 60 is preferably coupled to movable part 156 with optical body 42.Optical body 42 limits the divergence of the light beam 152 exiting fromthe edge of fiber 60 and guides light beam 152 to lens 68. An end pointof fiber 60 is positioned close to the focal plane of lens 68. Lens 68transforms light beam 152 into collimated beam 151.

[0110] Actuators 76, 77, and electrodes 157 and 159 are formed in basemember 32. This actuator design allows changing angular position ofmovable part 156 and 158. Actuators 76, 77, and electrodes 157 and 159allow the application of force to movable parts 156 and 158 andresulting in a change in their position. Actuators 76 and 77 can beelectrostatic, electromagnetic, thermo-mechanical, piezoelectric,electroactive polymers and the like. Lens 68 moves together with movablepart 156 and 158. FIG. 12(a) shows movable parts 156, 158 and lens 68 inan equilibrium position when no force is applied to movable part 156from actuators 76 and 77. FIG. 12(b) illustrates the position of movableparts 156, 158 and lens 68 after actuator 77 has applied some force tomovable part 158. As can be seen from FIGS. 12(a) and FIG. 12(b),changing angular position of movable part 156 allows changes in theangular position of lens 68 and the direction of light beam 151.Therefore, light beam 151 can be spatially redirected by the interactionof actuator 76 and 77 with movable parts 156 158.

[0111] Frame 154 is coupled with movable parts 156 and 158 bysuspensions 155 and 160, as illustrated in FIG. 12(b). Suspensions 155and 160 are strong enough to withstand mechanical forces applied tomovable parts 156 and 158 during wafer processing, including waferseparation, die handling and transmitting directing device 54 assembly.Suspensions 155 and 160 can be flexible enough to provide angulardeflection of movable parts 156 and 158 by the force applied byactuators 76 and 77. Suspensions 155 and 160 also provide electricaland/or magnetic and/or thermal connection of movable parts 156 and 158with frame 154. For example, if actuators 76 and 77 employelectromagnetic actuation, and permanent magnets are located on or inbase member 32, then suspensions 155 and 160 transferring electricalcurrent to movable parts 156 and 158. Interaction of this electricalcurrent with the magnetic field of the permanent magnets creates aforce, resulting in the angular displacement of movable parts 156 and158 with lens 68.

[0112] Actuators 76 and 77 can also be thermo-mechanical or bimetallic.Thermo-mechanical actuators 76 and 77 can achieve larger forces anddeflections compared to electrostatic and electromagnetic actuators.Thermo-mechanical actuators 76 and 77 contain heater, not shown, whichheat at least a portion of suspensions 155 and 160. Thermo-mechanicalstresses created in suspensions 155 and 160, as a result of heating,creates angular displacement of movable parts 156 and 158 together withlens 68. Thermo-mechanical actuators 76 and 77 can be multi-layerstructures, including but not limited to metal—insulator—silicon, with athin layer of silicon dioxide, silicon nitride, silicon carbide, and thelike, used as an insulator. Single-layer thermo-mechanical actuators 76and 77 can also be used.

[0113] There are several options for the heater structure. With amulti-layer structure, the heater can be made on the metal layer,silicon layer, or on both in the electrical circuit. The heater iselectrically and thermally coupled with base 32. If thermo-mechanical,bimetallic, actuators 76 and 77 are used, then the electrical connectionof micro-machined die 153 with base member 32 can provide the necessarycurrent to the heater. The thermal connection between micro-machined die153 and base member 32 can provide sufficient thermal resistance to,create the necessary temperature gradient across suspensions 155 and160, and which is small enough to prevent overheating of movablestructures 156, 158 and lens 68.

[0114] With piezoelectric actuators 76 and 77, a piezoelectric material,not shown, can be applied to the top of micro-machined die 153 insuspensions 155 and 160. An applied voltage to the piezoelectricmaterial changes its linear dimensions. As a result, suspensions 155 and160 can be bent, and movable structures 156 and 158 are deflected. Thischanges the angular position of lens 68. In this embodiment,piezoelectric actuators 76 and 77 are preferably electrically coupledwith base 32. This coupling provides for the application of thenecessary voltage to the piezoelectric material.

[0115]FIG. 13(a) illustrates gimbal suspension of moveable part 156.Fiber 60 is coupled to moveable part 156 which moves in one angulardirection on torsion beams 155. Torsion beams 155 are coupled to outerframe or outer ring 158, which in turn, are connected by torsion beams160 to the frame 154. This suspension provides two-dimensional angularredirecting of the light beam. This gimbals works with electrostaticactuators 76 and 77 as illustrated in FIG. 13B. When voltage is appliedbetween moveable part 156 and one of the electrodes 157 or 159, theelectrostatic force tilts moveable part 156 with lens 68 and fiber 60,resulting in a redirection of the light beam from lens 68 in one angulardimension. In the same manner, the corresponding electrodes 157 or 159can move outer ring 158 and tilt or rotate it on torsion beams 160. Lens68, fiber 60 and the light beam are then redirected in another angulardimension.

[0116] With any torsional suspension, including gimbal, for highersensitivity the ratio of length to diameter of torsion suspension shouldbe larger. However, with long suspension, mechanical shock overloadprotection becomes worse. With the present invention, this problem issolves, as illustrated in FIG. 14. Torsion suspension 155 goes throughlimiting tubes 161 that are mechanically connected to frame 158. Thetorsion movement of the beams and the tilt of electrodes 157 or 159 arenot limited by tubes 161. However, when overload acceleration is appliedin either the X or Z directions, as in FIG. 14, then tubes 161 limit themotion of suspension 155 and the mechanical shock overload protection ofmoveable part 156.

[0117] Suspension 155 of moveable part 156 can be made as a system ofsprings, for example three or more. The springs can be flat, flatplanar, or flat transverse. Additionally, the springs can have differentgeometries such as beam structures, meandering, tethers, spiral, and thelike, and can be continuous, perforated flat, corrugated diaphragms, andthe like.

[0118]FIG. 15(a) shows top view of a one-fiber cell 162 of transmittingdirecting device 54 with actuator 76 or 77 according to one embodimentsof the present invention. FIG. 15(b) illustrates a cross-section ofone-fiber cell 162 of the transmitting directing device 54. One-fibercell 162 contains base member 32 which can be made from differentmaterials, including but not limited to ceramics, silicon and the like.Base member 32 is connected with micro-machined die 153 which includesframe 154 and movable parts 156 and 158. Micro-lens 68 is rigidlyconnected with the central area of movable part 156. Fiber 60 isconnected with movable part 156 and microlens 68 with optical body 42.Movable parts 156 and 158 have smaller thickness than frame 154.

[0119] In one embodiment, moveable parts 156 and 158 includes fourelectrodes 166 positioned around and coupled to microlens 68. Electrodes166 are isolated from frame 154 by an airgap 167 and are suspended byfour beams 164. Beams 164 also provide electrical connection of saidfour electrodes 166 with frame 154 with at least one conductive elementformed either on the surface of the frame or in the frame such assilicon, and the like. Movable part 156 and 158 can be formed, forexample, using wet chemical etching from one side of the silicon waferfollowed by the reactive ion etching from the opposite side of thesilicon wafer. Micro-machined die 153, which is silicon in oneembodiment, is mechanically and electrically connected with base member32 via connecting members 169. At least some of the connecting members169 can be electrically conductive. Some electrical potentials can betransferred to micro-machined die 153 from electrical circuits 165located on the surface or in the body of base member 32 using connectingmembers 169. For example, solder bumps can be used for the mechanicaland electrical connection.

[0120] In one embodiment, electrodes 157 are located on the surface ofbase member 32. Different electrical potentials can be applied tomovable structure 156 and to at least one of electrodes 157 and 159. Thedifference in electrical potentials between movable structure 156 and atleast one electrode 157 causes electrostatic force attracting movablestructure 156 to base member 32. When no electrostatic force is appliedto movable structure 156 it maintains in an equilibrium position. Theelectrostatic force applied to movable structure 156 results in changeto the angular position of movable structure 156. Micro-lens 68 alsochanges its angular orientation. This redirects the light beam, whichgoes through micro-lens 68.

[0121]FIG. 16(a) illustrates a top view of one-fiber cell 162 oftransmitting directing device 54 with actuators 76 or 77 according toanother embodiment of the present invention.

[0122]FIG. 16(b) shows a cross-section of the FIG. 16(a) one-fiber cell162. The major difference in the one-fiber cell 162 of FIG. 16(a) incomparison with FIG. 15(a) is the different suspension 155 used formovable structure 156. The “meander” beams 170 have smaller bendingstiffness compared to straight beams 155 of FIG. 15(a). This allowslarger angular deflection of movable part 156 with lens 68 by applyingthe same voltage between electrode 157 and movable structure 156. Forthe same required deflection, the structure of FIG. 16(a) permits use ofa smaller voltage for actuator 76.

[0123]FIG. 17(a)-(b) illustrate different kind of suspension 155 usefulwith the present invention. Flat planar beams are utilized in FIG.17(a)-(b). Further the beams can be thin enough to be tethers that arepositioned diagonally so that electrodes 157 and 159 act as plates andprovide rotation or tilt of moveable part 156, lens 68 and fiber 60 indifferent angles. The advantage of this structure is that the diagonalsuspension 155 can be longer for the same size of the rectangular dieand allows a larger tilt for the same applied driving voltage.

[0124] The accuracy of the mutual angular alignment of transmitting andreceiving parts affects the optical losses between the input and outputchannels. With the present invention, the system that controls theposition of movable parts 156 and 158 should be accurate. In certainembodiments of the present invention, a closed loop, such as feedback orservo, is required to achieve this accuracy. In one embodiment of thepresent invention, control system 38 is closed loop and requires afeedback signal from the different beam positioning sensors. It will beappreciated that control system 38 can also be an open loop system.

[0125] Control system 38 provides the processing of the protocol data ofoptical switch 30, creating a system for driving actuator signals, andthen distributes these signals between different actuator 76 and 77according to the protocol. In the case of a closed loop systemarchitecture, control system 38 also processes the signals from thesensors and adjusts the actuator control signals depending on therequirements. Control system 38 also provides feedback to actuators 76and 77 to actively damp vibrations of the movable parts 156 and 158caused by either sharp switching from one port to another or bymechanical shock. High accuracy and stability requirements for aimingtransmitting arrays 32 into receiving arrays 36 often can not beprovided by existing mechanical sensors due their low sensitivity andlong term stability.

[0126] Balancing accuracy and increasing complexity can be achieved witha double closed loop control system 38. In this embodiment, controlsystem 38 has two feedback loops. One is based on mechanical sensorsbuilt in the suspensions 155 and 160. In this embodiment, mechanicalsensors provide control system 38 with the information about currentposition of suspensions 155 and 160 and, therefore, the orientation ofthe light beam. Sensors can be included with each port of transmittingand receiving arrays 32 and 36. Transmitting and receiving arrays 32 and36 can have a limited number of sensors with fixed locations relative tothe locations of the collimators. From time to time, according to theprotocol, the mechanical sensors are recalibrated with the assistance ofthe optical sensors, and provide accurate information about thepositioning of the light beam.

[0127] Micro-machined die 153 can contain one or several sensors, notshown, for the closed loop that generate electrical signals proportionalto the deflection of certain elements of the suspensions 155 and 160. Aset of signals from the sensors determine the position of movablestructure 156 and, therefore, the spatial orientation of lens 68. Thesensors can be capacative, electromagnetic, piezoelectric,piezoresistive, and piezo-junction (piezotransistor), and the like.Electrical signal from the sensors can be used for different purposesincluding but not limited to, (i) aiming the light beam to differentreceiving arrays 36, (ii) mechanical shock damping, (iii) sensevibrations after switching damping, (iv) calibration in production, (v)on-field self test, and (vi) failure detection. Capacitive sensorsemploy capacitance change between base member 32 and movable structure156. The measured change of capacitance corresponds to the change of theangular position of lens 68.

[0128] Electromagnetic sensors use the effect of voltage generation inthe case of a moving conductor in a magnetic field. The magnetic fieldcan be created by one or more permanent magnets located on or in basemember 32. One or more conductors can be located on suspensions 155 and160 and/or on movable structure 156.

[0129] Piezoelectric sensors also can be used with suspensions 155 and160. Mechanical stress in suspensions 155 and 160 due to theirdeflection caused by actuators 76, 77 creates electrical charge in thepiezoelectric film that can be detected by control circuitry.

[0130] Piezoresistive sensors and piezo-junction sensors are based onthe same physical effect, the dependence of the carriers mobility onmechanical stress in semiconductor materials. This effect causes changesof the resistance in an amount that is proportional to the stress in thepiezoresistor area. It also causes changes of the p-n junctionparameters under stress and this change can be effectively amplified inpiezotransistor-based circuits. Both bipolar and CMOS piezotransistorscan be used. Different circuits with piezoresistors and piezotransistorscan be used. For example, a Wheatstone bridge or four-terminal resistor(X-ducer) can be used in a piezoresistive sensor circuit.Piezotransistors combined in different circuits can provide smallerareas on the surface of suspensions 155 and 160, orders of magnitudehigher sensitivity and either analog or digital output.

[0131]FIG. 18(a)-18(e) illustrates different examples of suspensions andelectrodes for actuators 76 or 77. The number of possible embodiments ofthese suspensions and associated movable parts is not limited by thefollowing examples.

[0132]FIG. 18(a) shows that electrodes 172 are made as circular platesso that they can provide equal maximum tilt when one of the edges ofelectrode 172 travels down in different angular directions. The maximumangular deflection in any direction is determined by a gap 168,illustrated in FIG. 18(b) between electrodes 172 and actuators theelectrostatic plates of 174, 176, 178, and the like, of an actuator 76.

[0133] The number of electrostatic plates 174, 176, 177, 178 of anactuator 76 can vary. By way of example, without limitation, actuator 76in FIG. 18(a) includes eight electrostatic plates, 174, 176, 177, 178and so on. The angle of position of moveable part 156 depends on whichelectrostatic plates 174 and so on, receive an applied voltage. Applyingthe voltage to either plates 174, 176, 177, or 178, can change thetwo-dimensional angular position of moveable part 156.

[0134]FIG. 18B illustrates a simple flat structure of electrodes 157 and159 the suspension. In this case the suspension and electrodes 157, 159are located in the same plane.

[0135]FIG. 18(c) shows a different embodiment of suspension andelectrodes 157, 159. In this embodiment, electrodes 172 can becontinuously circular without slots for the suspension. Suspension isprovided by beams 196, which can be nonuniform in thickness and havethinner sections 198. When a voltage is applied to plates 174 or 178 theelectrostatic force attracts corresponding parts of moveable member 172.This results in a change of the angle or position of fiber 60 and beam196 to create the required tilt or angle of the outgoing light beam.

[0136]FIG. 18(d) illustrates another suspension embodiment of thesuspension which has flat transverse beams 190 optionally one or moresprings 192 is included as part of the suspension. This type ofsuspension is also illustrated three-dimensionally in FIG. 19. Whenvoltage is applied between electrodes 178 and 172, the electrostaticforce attract electrode 172 and all movable parts of the moveable membertogether with fiber 60 will tilt. Springs 192 make the suspension moreflexible for tilt and less voltage is required for the same degree oftile.

[0137] The suspension of FIG. 18(e) is a variation of moveable part 156suspension and is illustrated three-dimensionally in FIG. 20. In theFIG. 18(e) embodiment, moveable part 156 is a cylinder 204 with beams200, FIG. 20. Beams 200 can optionally have thinner sections 202. Thesethinner sections 202 can be used as a concentrator of mechanical stressfor increasing sensitivity of the sensors positioned on beams 200. Thecylindrical shape 204 has several advantages including, (i) permittingelectrodes 172 to be more rigid so they can transfer their motion to theangular motion of fiber 60 more accurate and (ii) does not increase themass of the movable part because cylinder 204 is hollow. The sidewall ofcylinder 204 can also be used as an additional surface for electrode 172to increasing sensitivity/efficiency of actuator 76. Actuator plate 178can also be expanded on the internal cylindrical part 206 as shown inFIG. 18(e). When electrostatic voltage is applied to plate 178, it isalso applied to electrode 206 that is electrically coupled to plate 178.The electrostatic force acts between plate 178 and electrode 172 andalso between plate 206 and moveable surface of cylinder 204. The resultis an increase of the electrostatic force and a decrease in the requiredvoltage required to tilt electrode 172 and optical body 42 to the sameangle.

[0138]FIG. 21(a)-(b) illustrate an embodiment of electrostatic actuationof optical switch 30 for eight angular positions. For example, when thevoltage is applied on steady electrodes 174 and 176, then moveable plate190 moves toward the +Y direction. When the voltage is applied on theplates, for example, 182 and 180, then moveable plate 194 is attractedto the base and moves toward the −Y direction. Correspondingly, when thevoltage is applied to 176 and 177, then the entire moveable part 156 istilt toward the +XY direction. Thus, changing the combination of thevoltage applied to different electrodes can change the angle orpositions of lens 68 and the outgoing light beam. In provides discreteor digital positioning of the light beam.

[0139]FIG. 22(a)-22(f) illustrates another suspension embodiment wherefiber 208 serves as a suspension for moveable part 156. In thisembodiment, moveable part 156 has a circular disk that is fixed on theend of fiber 208.

[0140]FIG. 22(a) shows a top view of one transmitting or receiving cellthat includes frame 154 and moveable plate 210 fixed at the end of fiber208. Moveable plate 210 is at a distance 211 away from electrodes 174 asshown in FIG. 22(b).

[0141] Electrodes 174 can be sectors of a circle. In a neutral position,when the voltage is not applied to any of the electrodes 174, moveableplate 210 stays in the neutral position, see FIG. 22(b) and the lightexits from fiber 208 in a straight upward direction.

[0142] When the voltage is applied to one of the electrodes 174, thenmoveable plate 210 bends toward this electrode 174 because of theelectrostatic force applied to this capacitor. This force tilts moveableplate 210 and deflects the end of fiber 208 to redirecting the lightbeam.

[0143]FIG. 22(c) illustrates the same cross section of the same kind ofredirecting mechanism with the only difference being that the centralpart of moveable plate 210 is a cylinder 212 which allows to extend theend of fiber 208 to extend above moving plate 210. This embodimentproduces larger linear deflections at the end of fiber 208 with the sameangular deflection of the fiber 208 in the area that serves as asuspension of the whole redirecting mechanism.

[0144]FIG. 22(d) illustrates, in cross-section, the redirectingmechanism, which can further include micro-lenses 68 and 69 incorporatedin cylindrical micro-collimator 212 of moveable plate 210. Lenses 68 and69 provide focusing or collimation.

[0145] The redirecting mechanism illustrated in FIG. 22(e) has acylindrical moving plate similar to that of FIG. 18(e). In thisembodiment, the suspension is also fiber 208 itself. When voltage isapplied to electrode 174 then the electrostatic force between electrode174 and moveable plate 210 attracts moveable plate 210 toward electrode174.

[0146] An additional electrode 214, positioned on an interior of frame154, also serves as an electrode for the electrostatic actuator. Theadditional electrostatic force between electrode 214 and cylinder 204attracts this side of the cylinder toward electrode 214. This increasesthe efficiency of actuator 76 by increasing deflection or angle or tiltof moveable plate 210 for the same driving voltage applied to electrodes174 and 214, or decreases the required voltage for the same deflectionof fiber 208.

[0147] The redirecting mechanism of FIG. 22(f) is a variation the FIG.22(e) embodiment. In FIG. 22(f) lens 68 is fixed at the end of cylinder204, creating a micro-collimator that is integrated with the movablepart 156 of actuator 76.

[0148] FIGS. 23(a)-23(f) illustrate different embodiments of lightredirecting mechanisms of the present invention.

[0149]FIG. 23(a) illustrates redirection of light with fiber 223,optical body 42 and lens 68 rotating or moving the light beam out oftransmitting array 32. In some cases, one lens 68 cannot provide qualitylight beam collimating and additional lens are required. The system oflens and micro-lenses can be moveable together in optical body 42.

[0150] In FIG. 23(b), an additional lens 220 is provided that is notmoveable. Lens 220 serves as an additional focusing or collimating lensand transmits the redirected beam.

[0151] In FIG. 23(c), the end of fiber 223 has its own collimating orfocusing micro-lens. The end of fiber 223 is preferably positioned at adistance to lens 220 that is selected in order for the beam exitingfiber 223 is collected by lens 220. The end of fiber 223 is redirectedwith the assistance of moveable part 222 which also redirects the lightbeam. This embodiment enables optical body 42 to be lightweight andrequires only a small redirection. Optical losses experienced in theFIG. 23(c) embodiment can be resolved in the FIG. 23(d) embodiment wherethe gap between the end of fiber 223 and lens 220 is filled with anoptically transparent material 225. Optically transparent material 225does not prevent free movement of the end of fiber 223 and provides anoptical matching of fiber 223 with lens 220 in order to decrease opticallosses

[0152] Referring now to FIG. 23(e), fiber 223 is stationary and caninclude its own micro-lens or micro-collimating system. A distal end offiber 223 is located at an input of waveguide 221. Waveguide 221 ismechanically coupled to movable part 226 of actuator 76. The mechanicalsystem of angular rotation of waveguide 221 is made in such a way thatthe pivot point is located close to the distal end of fiber 223. As aresult, with angular redirection of waveguide 221 the input of waveguide221 is always optically coupled with the distal end of fiber 223. Thelight beam exiting fiber 223 enters waveguide 221. Waveguide 221 thenredirects the beam toward the corresponding receiving array 36. Thisembodiment has the advantage that there is no need to move and bendfiber 223. The overall suspension of movable part 156, including thesuspension and along with the springy properties of fiber 223, is moreflexible and requires less driving voltage for a selected tilt. Thisembodiment is also advantageous because of its simplification in theassembling process.

[0153] Waveguide 221 can also be combined with microcollimating system227 as illustrated in FIG. 23(f). Micro-collimator system 227 ismechanically and optically coupled with movable part 156 and waveguide221. Micro-collimator 227 can include several lenses 68, 69 for bettercontrol of the beam shape.

[0154] FIGS. 24(a)-(f) illustrates different versions of moveable part156 of fiber 223. When fiber 223 is used as a suspension, then theentire thickness can be used as in FIG. 24(a). In this embodiment, theend of fiber 223 is coupled optically and mechanically with lens 68 andmoveable part 156. When the mechanical suspension other than fiber 223itself is used, then the flexibility of the end of fiber 223 can becritical. In this embodiment, the end of fiber 223 can be thinned asshown in FIG. 24(b). The end of fiber 230 can be thinner than itsinitial cladding. This thinner fiber 230 provides more flexibility,ability to bend, and is connected to lens 68 and moveable part 156.

[0155] In FIG. 24(c) fiber 223 is again thinned from its initialcladding except the very distal end of fiber 223 is thinker. Thisenhances the mechanical coupling with lens 68.

[0156] In another embodiment, illustrated in FIG. 24(d), circular orother geometric trenches 234 are made at the end of fiber 223. Thisstructure provides enough flexibility for the end of fiber 223 to bebent and while preventing the maximum curvature, maximum bending, offiber 223 and reduces the possible optical losses. The geometry oftrenches 234 and their pitch can be designed in such a way that themaximum bending of fiber 223 does not exceed the maximum allowablebending for a required level of optical loss.

[0157]FIG. 24(e) illustrates another embodiment of the end of fiber 223.In this embodiment, lens 236 is bonded or sealed directly to fiber 223,or made from the fiber material. Moveable part 156 is connected directlyto the end of fiber 223. The flexible part of fiber 223 has a smallerdiameter than the diameter of its cladding. Additionally, as in FIG.24(f), lens 236, for example a GRIN lens and the like, is attacheddirectly to fiber 231 and moveable part 156 is also bonded directly tothe end of fiber 231.

[0158] FIGS. 25(a)-25(b) illustrate different embodiments of opticallytransparent media between transmitting array 32 and receiving array 36.The optically transparent media can be vacuum, gas, air, liquid, gel,and the like. In FIG. 25(a) optically transparent media is housed in aclosed volume 250 filled with optically transparent material 252. Closedvolume 250 has at least two transparent windows 256 and 257 which allowtransmitted light beams to travel from transmitting array 32 toreceiving arrays 36.

[0159] Referring now to FIG. 25(b), closed volume 250 has multiple setsof windows 258 and 260 for every transmitting and receiving arrays 32and 36. Windows 258 and 260 can be optical grating lenses.

[0160] The foregoing description of a preferred embodiment of theinvention has been presented for purposes of illustration anddescription. It is not intended to be exhaustive or to limit theinvention to the precise forms disclosed. Obviously, many modificationsand variations will be apparent to practitioners skilled in this art. Itis intended that the scope of the invention be defined by the followingclaims and their equivalents.

What is claimed is:
 1. An optical switch, comprising: a plurality oftransmitting devices including a plurality of optical fibers; aplurality of receiving devices including a plurality of optical fibers;wherein at least a portion of the transmitting devices simultaneouslyfocus and direct transmitter output beams from the plurality oftransmitting devices to the plurality of receiving devices.
 2. Theswitch of claim 1, wherein the plurality of transmitting devices areintegrated on a single substrate.
 3. The switch of claim 1, wherein theplurality of receiving devices are integrated on a single substrate. 4.The switch of claim 1, wherein the plurality of transmitting devicesincludes a plurality of focusing devices, each of an optical fiber fromthe plurality of transmitting devices being coupled to at least onefocusing device.
 5. The switch of claim 1, wherein the plurality oftransmitting devices includes a plurality of directing devices, each ofan optical fiber of the plurality of transmitting devices being coupledto at least one directing device.
 6. The switch of claim 1, wherein theplurality of transmitting devices includes a plurality of focusingdevices and a plurality of directing devices, wherein each of a focusingdevice is coupled to a directing device.
 7. The switch of claim 4,wherein each focusing device includes at least one lens.
 8. The switchof claim 7, wherein each lens is selected from a regular lens, a GRINlens, a diffractive grated lens, and a Fresnel lens.
 9. The switch ofclaim 4, wherein at least a portion of the focusing devices include amicro-collimator.
 10. The switch of claim 4, wherein at least a portionof the focusing devices include an optical waveguide.
 11. The switch ofclaim 4, wherein at least a portion of the focusing devices include avariable-focus lens.
 12. The switch of claim 5, wherein each directingdevice is a micro-mechanical device.
 13. The switch of claim 5, whereinat least a portion of the directing devices include an opticalwaveguide.
 14. The switch of claim 12, wherein each micromechanicaldevice includes an actuator.
 15. The switch of claim 14, wherein eachactuator is selected from an electro-static actuator, an electromagneticactuator, a piezoelectric actuator, a thermo-mechanical actuator and apolymer actuator.
 16. The switch of claim 15, wherein the polymeractuator is an electro-active polymer actuator, an optical-activepolymer actuator, a chemically active polymer actuator, a magneto-activepolymer actuator, an acousto-active polymer actuator and a thermallyactive polymer actuator.
 17. The switch of claim 12, wherein eachmicromechanical device includes a suspension member that providesmovement of a distal portion of an optical fiber of the plurality oftransmitting optical fibers.
 18. The switch of claim 17, wherein eachsuspension member includes at least one elastic deformation member thatprovides a mechanical coupling between a substrate and the movable partof the directing device.
 19. The switch of claim 4, further comprising:an optical body positioned between each focusing device and a distal endof each of a optical fiber of the plurality of transmitting opticalfibers.
 20. The switch of claim 19, wherein the optical body includes atleast one of a solid optical transparent material, a liquid opticallytransparent material, a gaseous optically transparent material, a geloptically transparent material.
 21. The switch of claim 1, wherein atleast a portion of the receiving devices are directed to receive thetransmitter output beams from the plurality of transmitting deviceswhile simultaneously focusing the incoming beams into the plurality ofoptical fibers of the plurality of receiving devices.
 22. The switch ofclaim 1, wherein the plurality of receiving devices includes a pluralityof focusing devices, each of an optical fiber of a plurality ofreceiving optical devices being coupled to at least one focusing device.23. The switch of claim 1, wherein the plurality of receiving devicesincludes a plurality of directing devices, each of an optical fiber of aplurality of receiving optical devices being coupled to at least onedirecting device.
 24. The switch of claim 1, wherein the plurality ofreceiving devices includes a plurality of focusing devices and aplurality of directing devices, wherein each of a focusing device iscoupled to a directing device.
 25. The switch of claim 22, wherein eachfocusing device includes at least one lens.
 26. The switch of claim 22,wherein at least a portion of focusing devices include amicro-collimator.
 27. The switch of claim 22, wherein at least a portionof the focusing devices include an optical waveguide.
 28. The switch ofclaim 22, wherein at least a portion of focusing devices include avariable-focus lenses.
 29. The switch of claim 25, wherein each lens isselected from a regular lens, a GRIN lens, a diffractive grated lens,and a Fresnel lens.
 30. The switch of claim 23, wherein each directingdevice is an micro-mechanical device.
 31. The switch of claim 23,wherein at least a portion of the directing devices include an opticalwaveguide.
 32. The switch of claim 30, wherein each micromechanicaldevice includes an actuator.
 33. The switch of claim 32, wherein eachactuator is selected from an electro-static actuator, an electromagneticactuator, a piezoelectric actuator, a thermo-mechanical actuator and apolymer actuator.
 34. The switch of claim 33, wherein the polymeractuator is an electro-active polymer actuator, an optical-activepolymer actuator, a chemically active polymer actuator, a magneto-activepolymer actuator, an acousto-active polymer actuator and a thermallyactive polymer actuator.
 35. The switch of claim 30, wherein eachmicromechanical device includes a suspension member that providesmovement of a distal portion of a transmitting optical fiber of theplurality of transmitting optical fibers.
 36. The switch of claim 35,wherein each suspension member includes at least one elastic deformationmember that provides a mechanical coupling between a substrate and atleast a portion of each micro-mechanical device.
 37. The switch of claim22, further comprising: an optical body positioned between each focusingdevice and a distal end of each optical fiber of the plurality ofreceiving devices.
 38. The switch of claim 37, wherein the optical bodyincludes at least one of a solid optical transparent material, a liquidoptically transparent material, a gaseous optically transparentmaterial, a gel optically transparent material.
 39. The switch of claim1, wherein at least a portion of transmitting devices are MEMS devices.40. The switch of claim 4, wherein at least a portion of focusingdevices are MEMS devices.
 41. The switch of claim 5, wherein at least aportion of directing devices are MEMS devices.
 42. The switch of claim22, wherein at least a portion of focusing devices are MEMS devices. 43.The switch of claim 23, wherein at least a portion of directing devicesare MEMS devices.
 44. The switch of claim 25, wherein at least a portionof lenses are MEMS devices.
 45. The switch of claim 1, wherein each of atransmitting device includes a fiber placement cavity.
 46. The switch ofclaim 1, further comprising at least one transmitter substrate with aplurality of fiber placement cavities, each of a fiber placement cavitycorresponding to a transmitting device of the plurality of transmittingdevices.
 47. The switch of claim 46, further comprising at least onereceiver substrate with a plurality of fiber placement cavities, each ofa fiber placement cavity corresponding to a receiving device of theplurality of receiving devices.
 48. The switch of claim 47, wherein eachof a transmitter device includes a focusing device and a directingdevice positioned adjacent to a fiber placement cavity.
 49. The switchof claim 48, wherein each of a receiver device includes a focusingdevice and a directing device positioned adjacent to a fiber placementcavity.
 50. The switch of claim 46, wherein each of a transmitter deviceincludes a focusing device and a directing device at least partiallypositioned in a fiber placement cavity.
 51. The switch of claim 50,wherein each of a receiver device includes a focusing devices and adirecting device at least partially positioned in a fiber placementcavity.
 52. The switch of claim 49, wherein each directing deviceincludes a suspension member that provides movement of a distal portionof a transmitting or receiving optical fiber.
 53. The switch of claim51, wherein each directing device includes a suspension member thatprovides movement of a distal portion of a transmitting or receivingoptical fiber.
 54. The switch of claim 1, further comprising: a firstsubstrate coupled to the plurality of transmitting devices that includea plurality of transmitting optical fibers, a plurality of focusingmembers and a plurality of directing members; a second substrate coupledto the plurality of receiving devices that include a plurality ofreceiving optical fibers, a plurality of focusing members and aplurality of directing members.
 55. The switch of claim 54, wherein atleast a portion of the receiving devices are directed to receive thetransmitter output beams from the plurality of transmitting deviceswhile simultaneously focusing the incoming beams into the plurality ofoptical fibers of the plurality of receiving devices.
 56. The switch ofclaim 54, wherein the first and second substrates each include aplurality of fiber placement cavities.
 57. The switch of claim 56,wherein a cross-sectional dimension of a fiber placement cavity isgreater than the size of the components positioned in the cavity. 58.The switch of claim 54, wherein the plurality of transmitting devicesincludes a plurality of elastic deformation members that provide amechanical coupling between the first substrate and a movable parts ofdirecting devices.
 59. The switch of claim 54, wherein the plurality ofreceiving devices includes a plurality of elastic deformation membersthat provide a mechanical coupling between the second substrate and amovable parts of directing devices.
 60. The switch of claim 1, furthercomprising an optically transparent media between transmitting andreceiving devices where light beams from said transmitting devices canmutually intersect on their way to corresponding receiving devices; 61.The switch of claim 60, wherein the optically transparent media includesa vacuum, a solid optically transparent material, a liquid opticallytransparent material, a gaseous optically transparent material, a geloptically transparent material.
 62. The switch of claim 60, whereinoptically transparent media is a system of lenses between transmittingand receiving devices.
 63. The switch of claim 62, wherein each lens isselected from a regular lens, a GRIN lens, a diffractive grated lens,and a Fresnel lens.
 64. The switch of claim 1, wherein a number oftransmitting devices and a number of receiving devices are the same. 65.The switch of claim 1, further comprising: a control system coupled tothe plurality of transmitting devices and plurality of receivingdevices, the control system providing control signals that coordinatepositioning of transmitting devices and receiving devices.
 66. Theswitch of claim 1, further comprising: at least one sensor coupled tothe plurality of transmitting devices and the control system; and atleast one sensor coupled to the plurality of receiving devices and thecontrol system.
 67. The switch of claim 66, wherein each of theplurality of transmitting and receiving devices includes at least onephotosensitive sensor.
 68. A method for optical switching between inputfiber channels output fiber channels comprising: providing a pluralityof transmitting devices including a plurality of optical fibers and aplurality of receiving devices including a plurality of optical fibers;and simultaneously focusing and directing at least a portion of thetransmitter output beams from the plurality of transmitting devices tothe plurality of receiving devices.